TB does not always increase viral load.
A recent study published in the Journal of Acquired Immune Deficiency Syndromes shows that one-quarter of Ugandan patients co-infected with TB and HIV had a viral load below 10 000 copies/ml. TB is usually associated with an increase in viral load.
Two studies involving a total of 202 HIV-positive patients with sputum smear-positive TB were reported by the investigators. Median baseline viral load was approximately 40 000 copies/ml and the median CD4 cell count was 472 cells/ [mm.sup.3].
However, 49 patients had a baseline viral load below 10 000 copies/ml, with 12 of these individuals having a viral load below 1 000 copies/ml.
The investigators compared the 40 patients who had a viral load below 10 000 copies/ ml to the 153 individuals with higher viral loads. There was no difference between these patients with regard to age, sex or severity of TB disease. Nor did CD4 cell count differ.
The investigators then looked at the effect initiating TB therapy had on viral load. When TB treatment was started, 19 (21%) of these patients had a viral load below 10 000 copies/ml. The investigators found that after 3 months of TB therapy, patients whose baseline viral load was above 10 000 copies/ml were significantly more likely to experience a fall in their viral load of at least 0.5 [log.sub.10] (p=0.001).
However, patients whose viral load was below 1 000 copies/ml when they started TB treatment were significantly more likely than patients with a higher baseline viral load to experience an increase in their viral load of at least 0.5 [log.sub.10].
The investigators note that multiple studies have observed an association between active TB and higher viral load. They write, 'Contrary to these observations, we detected low-level HIV viremia ... in almost 25% of Ugandan patients with untreated HIV-TB coinfection in 2 different clinical trials and found that low-level viremia was not related to baseline CD4 cell count or severity of TB.'
They conclude that investigation of 'host and viral factors may shed further light on potential causes of low-level HIV viremia in the setting of active TB and provide additional insights into HIV and TB pathogenesis'.
Srikantiah P, et al. J Acquir Immune Defic Syndr 2008; 49: 458-460.
* This material is based on an original copyright publication by NAM Publications, an independent HIV information charity based in the UK. Permission for this translation has been granted by NAM. The original publication can be viewed at www.aidsmap.com. NAM cannot be held responsible for the accuracy of the translation nor the local relevance of the text.
|Printer friendly Cite/link Email Feedback|
|Title Annotation:||AIDS briefs; tuberculosis|
|Publication:||CME: Your SA Journal of CPD|
|Date:||Feb 1, 2009|
|Previous Article:||Treadmill exercise and resistance training in patients with peripheral arterial disease.|
|Next Article:||HIV prevalence may decline because the most vulnerable will die first.|